The Caumasee is one of the most beautiful lakes in Switzerland: a small, intensely turquoise pool in the forest about 20 minutes' walk downhill from Flims village. The colour comes from glacial minerals in the water. In summer the lake is warm enough to swim — it sits in a sheltered hollow that traps heat — and there is a small beach with a restaurant and changing facilities.
The walk down from the village through the spruce forest is pleasant in itself. In the height of summer the lake can get busy on weekends; come early or on a weekday to have it to yourself. Kayaks and paddleboards can be rented on site.